ListView结合ContextMenu 获取点击项的Position

ContextMenu称为上下文菜单，一般在控件上长按时弹出。今天我们学习ContextMenu的用法，这里与listview相结合，先在ListView显示几个Item,然后在Item上长按，弹出一个菜单（就是ContextMenu）,点击菜单上的项目，提示刚才长按的Item的Position.

main.xml 里就一个ListView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<ListView  android:id="@+id/lv"
    android:layout_width="fill_parent" 
    android:layout_height="wrap_content" 
    android:text="@string/hello"
    />
</LinearLayout>

package com.pocketdigi.com;
 
import java.util.ArrayList;
 
 
import android.app.Activity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
 
public class main extends Activity {
	 /** Called when the activity is first created. */
	ListView lv;
	ArrayAdapter<String> Adapter;
	ArrayList<String> arr=new ArrayList<String>();
	//定义菜单项
	protected static final int Menu_Item1=Menu.FIRST;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        lv=(ListView)findViewById(R.id.lv);
        //添加ListView项
    	arr.add("123");
    	arr.add("234");
    	arr.add("345");
    	Adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, arr);
    	lv.setAdapter(Adapter);
    	lv.setOnCreateContextMenuListener(MenuLis);
    }
    ListView.OnCreateContextMenuListener MenuLis=new ListView.OnCreateContextMenuListener(){
		@Override
		public void onCreateContextMenu(ContextMenu menu, View v,
				ContextMenuInfo menuInfo) {
			// TODO Auto-generated method stub
			//添加菜单项
			menu.add(Menu.NONE,Menu_Item1,0,"获取position");
		}
 
    };
    //选中菜单Item后触发
    public boolean onContextItemSelected(MenuItem item){
    	//关键代码在这里
        AdapterView.AdapterContextMenuInfo menuInfo;
        menuInfo =(AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
        //输出position
    	Toast.makeText(main.this,String.valueOf(menuInfo.position), Toast.LENGTH_LONG).show();
    	 return super.onContextItemSelected(item); 
 
    }
 
}

List 中显示context Menu

// get the list view

ListViewlist=(ListView)findViewById(R.id.list);

//setadapterbeforeregisteringthecontextmenu

list.setAdapter(adapter);

//registeritforthecontextmenu

registerForContextMenu(list);